The biotechnological control of pitch in paper pulp manufacturing

At present, microbial and enzymatic preparations for the control of triglyc eride-containing pitch deposits during the manufacture of mechanical and su lfite paper is commercially available. However, biotechnological products f or pitch control in other pulping processes, such as alkaline pulping, are underdevelopment. These products include new fungi for the removal of stero ids involved in pitch deposit formation in chlorine-free pulps,to be used a s a biological pretreatment of wood before pulping. Simultaneously, tailor- made enzymes are being produced using protein-engineering techniques, enabl ing the specific removal of pitch contaminant compounds from paper pulp.